Presence-based capability discovery is currently not supported for the full suite of service included in RCS. RCS release 6 supports “in-call services” wherein content can be shared in the context of a telephone call. However, when capability discovery via presence is used, ambiguity can arise in multi-device scenarios. Capability discovery is used to determine which in-call services to offer (e.g., which service icons to illuminate on an end-user's graphical user interface operational on a user device, although user experience details can vary from one device implementation to another).